Process for the production of a colored sound film



Dec. l 1936; B. GASPAR 2,052,304

PROC ESS FOR THE PRQDUCTION OF A CCLORED SOUND FILM Filed Nov. 16, 1932 LATENT \SOUND IMAGE YELLOW ONLY IN ONE LH R PE/ TED Bur N07 DEVELOPED METALLIC SILVER DEPOSIT BLACK Gnu/VD zEcogo ONLY IN ONE LAYEJE DEVELOPED AND FIXED DYEST'UF'FST/LL DIFFUSELY PRESENT IN ALL LAYERS TREAT ENTIRE F/LM WITH BATH FOR DESTROY/N6 DYESTUFF LOCALLY WHERE N I R I ON LAYEQ OF SOUND RA K- COLOR SOUND DrEsruFF REMOVED REcoEo ONLY FROM OTHER LAYERS /s (PRESENT.

RESULT/N6 MATEE/AL MULTI- COLOR COLOR SOUND RECORD I MAGE PEI (TED BUT -01- DEVELOPED ""(QwKQ SUPPORT k m\& mm

MAGENTA GREEAPBLUE METALLIC SILVER oEpos/r ALLY DEVELOPED SOUND TRACK TOT BLHCKENED BLACK SOUND RECORD.

AND FIXED.

l- DYESTUFF' STILL. DlFFU-SELY PRESENT IN ALL LA YERS- TEE l7 ENTIRE FILM WITH BAT'H FOE DESTROY/N6 DYEST'UFF LOCIQLL).

DECOLOR ZED SOUND TRACK LAYER DYEsTl/F'F DESTEOYEO ti iifam fifi ,I m WHERE SILVER WIminmmmmnmmmnmmm J r cow/e RECORD L v /N ONE LAYER RESULT/N6 MATERIAL We MM um-1 COLOEEE LV/AGE Zw w Patented Dec. 1, 1936 rnoonss FOR i 2,062,304 THE monuc'rron or A COLORED SOUND FILM Bla Gaspar, Berlin-Schoneberg, Germany Application November 16, 1932, Serial .No. 642,961

- In Germany November 19,1931

. 2 Claims.

It is of course well known to combine the production of a colored photographic picture with a *sound image, in order to obtain a combined picture and sound film. For this purpose it is usual to employ an imbibition, tanning or mordanting process, in which the image is colored subsequently by means of a water-soluble dyestufl.

It has been found that these toning, coloring or imbibition processes do not permit of a satisfactory projection, because, owing to the diffusion of the dyestufl in the layer there is an increase in the size of grain, which impairs the sharpness of the image. This is particularly apparent in the case of the sound record, in which the fine overtones or higher notes are greatly aiiected.

In order, therefore, to solve the problem of producing a colored picture and sound film, it has been necessary to devise a new process fulfilling three conditions:

(1) Density of the dyestufi deposit in proportion to the density ofv the silver image;

(2) A size o'f'grain in the dyestufideposit at least as fine as that of the silver image, or preferably even finer; I

(3) Coincidence between the color of the sound record and the sensitiveness of the photo-electric reproducing cell.

The present invention solves this problem in novel and reliable fashion, the sound recordbeing produced in the form a pure dyestufi-image. For this purpose it is possible either to color the emulsion prior to its application to the support, or to color diffusely the finished layer in a separate bath before or after the production of the.

silver image. In contradistinction to the known imbibition or tanning processes the invention employs non-diffusing dyestuffs. Dyestuffs of this nature are obtained in the known manner by fixing the dyestufi in the layer by mordanting or by the formation of a lake or a deposit on the layer. It is also possible to color the binding .agent of the light-sensitive or developed layer ii'fthe local destruction of the dyestufi taking place later is performed in acid reaction. If basic dyestuffs are employed, which are not fixed by one of the means stated, the destruction of the dyestufl must be eifected in an alkaline or neutral agent. I

By way of explanation reference may be made to the following example: The material employed for producing a combined picture and sound film is a' normal positive cinematograph film. Onto this there is copied by means of a positive, a black silver image, which is developed (01. sax-16.2) 7

and fixed in the usual fashion. The film is now colored entirely in diffuse fashion by immersion in a dyestufi solution, for example diamine pure blue FF (424), a film being obtained, via, a negative, in which both the picture portion as well as the sound record are colored blue.

This film is to remain difiusely colored in the picture portion, the sound portion being repre= sented by a blue dyestufi image. For this purpose the sound track is treated with a solution consisting of 'I'hiocarbamide g 5 Citric acid g 5 Water ocm as described in my co-pending application Serial No. 572,232. In this bath the dyestuiI is destroyed at the points of the silver deposit,but remains at the fixed points where there is. no silver deposit or only very little silver. In this manner a reversed image is obtained. From this image the then remaining silver is removed by the use of a silver dissolving agent. For this purpose there may be employed, for example, Farmer's reducer, which consists of an aqueous solution of sodium thiosulphate and potassium ferricyanide. The metallic silver is accordingly dissolved, and there remains a pure dyestuii image at the point of the sound record. The complete film, there- 'fore now comprises a diffusely colored blue picture portion and a pure blue dyestufi sound image. A

The dyestuff may be introduced into the layer at any desired time. Thus, for example, the desired dyestuif may be added to the emulsion prior to its application to the support, the exact amount thereof being determined by thecoloring properties of the dyestuff or according to other aspects of a specific nature, as in trick films. If the dyestufibleeds, the same will be made insoluble by a corresponding binder. For this purpose there may be employed the known mordants or substances which cause a lake or other deposit in the emulsion. Various dyestuffs do not require a particular binding agent, as they do not diffuse. These are acid, substantive or azo-dyestuiTs.

For a multi-color image there are produced the requisite number of colored emulsions, which are then poured oneupon the other or are applied to either side of the support. In two-color processes the one emulsion will be, for example, redorange and the other blue-green.

Three-color stock may comprise, for example, a purple-red layer, a yellow layer and a bluegreen layer, these layers likewise being applied to one or both sides of the support.

In multi-color material the sound record may be copied into any or all of the layers. If one layer is used, this will be selected so as to correspond with the sensitiveness of the reproducing cell. The remaining layers will be exposed either diffusely or not at all. If they are not exposed, the silver halide will not be varied upon the subsequent development, so that the same will afterwards be fixed in clear form. To destroy the dyestutf there will be employed an agent which destroys the dyestuif entirely, for example sodium hydrosulphite.

If the dyestufl has ben diffusely. exposed, the same will be destroyed with an acid thiocarbamide solution at all points, because the silver halide is developed diffusely upon the development.

Instead of destroying the dyestuif at the point not exposed to the sound record, 1. e., to make the film transparent, the dyestuif may also be allowed to remain. The sound is copied, for example, into the blue layer and the red layer exposed diffusely, while the yellow layer is not exposed. ,Upon the subsequent destruction of the dyestuif in the developed and fixed image by means of an acid thiocarbamide solution a blue sound image is accordingly obtained on a yellow ground.

If on the other hand the sound were produced evenly in all three layers, a subtractive black image would result. The destruction of the dye image at the position of the silver image may also be effected bymeans of coupled reactions, as made known by Luther and V. Holleben, or on previously treated silver images, by previously converting them into a mordant or tanning them and then causing a dyestuif-destroying agent to act on them. All these reactions have the advantage of being useful for the reproduction of sound by virtue of the fact that dyestufl that is already present is destroyed in the layer and is not merely subsequently allowed to diifuseinto a mordanted or tanned layer, since this mode of action actually produces the disturbing lack of sharpness.

Byway of explaining the invention, reference may be had to the accompanying flow sheet wherein:-

Figure 1 diagrammatically illustrates the process used in performing the invention to provide one type of material; and

, Figure 2 illustrates the practising of the process to provide an alternative type of material from that resulting in Figure 1.

According to the invention, all the above-mentioned agents which have a selective dye-stuff destroying effect are suitable for the production of sound images; they all produce good whites. The majority of the methods mentioned, however, are too troublesome, so that in practice one will mainly work in accordance with the methods of the processes of the prior inventions of the applicant, because these lead to the desired result in a single bath.

The methods referred to are suitable for the production of sound images both by the intensity process and the transversal process. For the latter process, the dye images are superior to the silver image because 'a thoroughly grainless image results.

The production of the characteristic of the layer that is necessary for the correct reproduction of sound may, according to the invention, be very readily influenced by alteration of the exagent are kept constant.

image have any desired shape (according to the I requirements) for the ,purpose of obtaining a distortionless reproduction of sound. It is, however, sufiicient if, for example, only two of the above mentioned factors are varied and, for example, the concentration of the color and the duration of action of the dyestuif-destroying It is therefore possible in the case of ordinary black-and-white sound copying, to directly obtain a definite characteristic for the copy merely by varying the exposure and the duration of the development. For the purpose of testing, measuring or checking, either a wedge or a degree scale is copied and this is compared with the copy matter in the light that is complementary to the color of the sound strip. With complementary light both are black or, according to the invention, comparison or comparative measurement with the black-and-white copy matter or checking wedge or degree wedge is not effected with the eye but with a photo-cell. Since the sensitivity of the eye is different from that of the photo-cell, the checking is, according to the invention, determined with the photo- 'cell that is intended for the sound reproduction and the copy matter or black-and-white degree with prior processes of the applicant's. The

sound image may, according to the invention, ex-

tend over one or more partial images or partial layers and be kept in any desired color. It is consequently possible toproduce sound images which are adapted to the sensitivity of various I photo-cells. For example, if the sensitivity of the photo-cell lies in the blue, a yellow sound image will be used. The sound image may be produced in one color or may form a mixture of a number of colors or, if required, may show a subtractive black. In the case of the intensity process, it is, according to the invention, to be preferred to restrict oneself, as much as possible, to one layer or partial layer or color in order to obtain an exact agreement. For this purpose, the colors of the remaining layers or partial layers can be bleachedi. e., destroyed-in the same bath or previously at the position of the sound trace or in the partial layers which cover the sound record, but which themselves contain no sound record, by localizing the quantity of silver, which effects the destruction of the dyestuff, simultaneously or subsequently by exposure, if required with suitably colored light, at the places in the layers in which no sound image is produced and the dye- Patent of the United States is:--

1. The method of producing multi-color kinematographic sound films in a pre-dyed photographic material comprising a support and a plurality of differently colored and light sensitive layers, which consists in photographically printing the sound image into the sound area of that layer, containing a dyestuif, whose color is complementary to the sensitiveness of the photoelectric devlce used in reproducing the film; developing the film, then treating the developed film with a dye destroying bath to destroy the dyestufl of the film selectively in proportion to the silver present in each layer, thereby removing the dyestuf! locally in the picture area of all of the layers and also locally in the sound area '0! the said layer which absorbs the light acting on the photo-electric cell, and removing the dyestufl' totally in the sound area of at least one other layer.

2. The method of producing multl-color kinematographlc sound films in a pre-dyed photographic materlal comprising a support and a plurality oi diflerently colored and light sensitive layers, which consists in photographically printing thesound image into the sound area of that colored layer which contains the dyestufl whose color is complementary to the sensitiveness of the photo-electric device'used in reproducing the film, diffusely exposing the sound area of at least one of the other layers, developing the film; then treating the developed film with a dyestufl destroying bath to destroy the dyestui! of the film selectively at the points where silver is present in each layer, thereby removing the dyestufl locally in the picture area of the layers and also locally in the sound area oi! that layer which absorbs the light acting on the photographic cell, and removing the dyestufl totally in the sound area of at least one other layer.

- BELA GASPAR. 

